Recently, as causes of diseases has been explained at the gene level based on results of human genome studies, demand for modification and biochemical analysis of biological specimens for the purpose of cure and prevention of diseases has increased. In addition, a technique for extracting and analyzing nucleic acid from biological specimens or cell-included specimens is demanded not only for diagnosis of disease but also in various fields such as new drug discovery and development, pretesting for viral or bacteria infection, and forensic medicine.
When nucleic acid is extracted, low-purity nucleic acid suppresses or disturbs a hybridization reaction such as with Southern blotting and a chemical reaction such as an enzyme reaction, and nucleic acid contaminating material dissolves nucleic acid to be tested and causes an error in measurement of nucleic acid quantity. Such a contaminating material includes a low-molecular material such as fat, an enzyme inhibitor, an enzyme such as a protein, a polysaccharide, and a polynucleotide.
In order to maintain a high-purity nucleic acid for application to molecular biology, various methods have been developed for solving the above-stated problems.
A method for extracting nucleic acid from a cell includes a method in which a specimen including the cell is solubilized by being processed with sodium dodecyl sulfate (SDS) or proteinase K and then protein is denaturalized and eliminated with penyol so as to refine the nucleic acid. However, the phenol extraction method takes a long time since it includes many steps, and nucleic acid extraction efficiency greatly depends on skill of a worker.
Therefore, recently, a kit using a column has become a basic tool for nucleic acid extraction in order to reduce the above-stated problems. This tool uses a method with silica or fiberglass that uniquely combines with nucleic acid, and the method dissolves a cell by processing it with a chaotropic reagent and refines nucleic acid molecules from protein and other materials in the cell by using a structural interactive mechanism between a water molecule and nucleic acid.
The fiberglass or silica film has a low-combination ratio with a cell metabolic material, and therefore relatively highly-concentrated nucleic acid can be obtained. Although this method is more simple compared to the phenol extraction method, this method has drawbacks in complexity of operation and time consumption because the chaotropic reagent or ethanol that strongly blocks an enzyme reaction such as PCR should be completely eliminated.
Recently, a method for directly refining nucleic acid by using a filter has been disclosed in the Internal Publication No. WO 00/21973. In this method, a cell is attached to a filter by passing a specimen through the filter, the attached cell is dissolved and filtered through the filter, and then nucleic acid attached to the filter is washed and eluted. However, in order to elute nucleic acid after attaching the cell to the filter, the filter should be selected in accordance with a cell type.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.